Full metadata
Title
Long-term EEG dynamics following traumatic brain injury in a rat model of post traumatic epilepsy
Description
Development of post-traumatic epilepsy (PTE) after traumatic brain injury (TBI) is a major health concern (5% - 50% of TBI cases). A significant problem in TBI management is the inability to predict which patients will develop PTE. Such prediction, followed by timely treatment, could be highly beneficial to TBI patients. Six male Sprague-Dawley rats were subjected to a controlled cortical impact (CCI). A 6mm piston was pneumatically driven 3mm into the right parietal cortex with velocity of 5.5m/s. The rats were subsequently implanted with 6 intracranial electroencephalographic (EEG) electrodes. Long-term (14-week) continuous EEG recordings were conducted. Using linear (coherence) and non-linear (Lyapunov exponents) measures of EEG dynamics in conjunction with measures of network connectivity, we studied the evolution over time of the functional connectivity between brain sites in order to identify early precursors of development of epilepsy. Four of the six TBI rats developed PTE 6 to 10 weeks after the initial insult to the brain. Analysis of the continuous EEG from these rats showed a gradual increase of the connectivity between critical brain sites in terms of their EEG dynamics, starting at least 2 weeks prior to their first spontaneous seizure. In contrast, for the rats that did not develop epilepsy, connectivity levels did not change, or decreased during the whole course of the experiment across pairs of brain sites. Consistent behavior of functional connectivity changes between brain sites and the "focus" (site of impact) over time was demonstrated for coherence in three out of the four epileptic and in both non-epileptic rats, while for STLmax in all four epileptic and in both non-epileptic rats. This study provided us with the opportunity to quantitatively investigate several aspects of epileptogenesis following traumatic brain injury. Our results strongly support a network pathology that worsens with time. It is conceivable that the observed changes in spatiotemporal dynamics after an initial brain insult, and long before the development of epilepsy, could constitute a basis for predictors of epileptogenesis in TBI patients.
Date Created
2012
Contributors
- Tobin, Edward (Author)
- Iasemidis, Leonidas (Thesis advisor)
- Tsakalis, Konstantinos (Committee member)
- Muthuswamy, Jitendran (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
x, 70 p. : ill. (some col.)
Language
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.15082
Statement of Responsibility
by Edward Tobin
Description Source
Viewed on May 1, 2013
Level of coding
full
Note
Partial requirement for: M.S., Arizona State University, 2012
Note type
thesis
Includes bibliographical references (p. 67-70)
Note type
bibliography
Field of study: Bioengineering
System Created
- 2012-08-24 06:29:11
System Modified
- 2021-08-30 01:45:44
- 2 years 8 months ago
Additional Formats